/*
 * Copyright (c) 2013 Grzegorz Kostka (kostka.grzegorz@gmail.com)
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup lwext4
 * @{
 */
/**
 * @file  ext4.h
 * @brief Ext4 high level operations (file, directory, mountpoints...)
 */

#include <ext4_config.h>
#include <ext4_types.h>
#include <ext4_misc.h>
#include <ext4_errno.h>
#include <ext4_oflags.h>
#include <ext4_debug.h>

#include <ext4.h>
#include <ext4_trans.h>
#include <ext4_blockdev.h>
#include <ext4_fs.h>
#include <ext4_dir.h>
#include <ext4_inode.h>
#include <ext4_super.h>
#include <ext4_block_group.h>
#include <ext4_dir_idx.h>
#include <ext4_xattr.h>
#include <ext4_journal.h>

#include "ext4_mp.h"

#include <stdlib.h>
#include <string.h>

/**@brief   Mountpoints.*/
static struct ext4_mountpoint s_mp[CONFIG_EXT4_MOUNTPOINTS_COUNT];

/****************************************************************************/

static bool ext4_is_dots(const uint8_t *name, size_t name_size)
{
    if ((name_size == 1) && (name[0] == '.'))
        return true;

    if ((name_size == 2) && (name[0] == '.') && (name[1] == '.'))
        return true;

    return false;
}

static int ext4_has_children(bool *has_children, struct ext4_inode_ref *enode)
{
    struct ext4_sblock *sb = &enode->fs->sb;

    /* Check if node is directory */
    if (!ext4_inode_is_type(sb, enode->inode, EXT4_INODE_MODE_DIRECTORY)) {
        *has_children = false;
        return EOK;
    }

    struct ext4_dir_iter it;
    int rc = ext4_dir_iterator_init(&it, enode, 0);
    if (rc != EOK)
        return rc;

    /* Find a non-empty directory entry */
    bool found = false;
    while (it.curr != NULL) {
        if (ext4_dir_en_get_inode(it.curr) != 0) {
            uint16_t nsize;
            nsize = ext4_dir_en_get_name_len(sb, it.curr);
            if (!ext4_is_dots(it.curr->name, nsize)) {
                found = true;
                break;
            }
        }

        rc = ext4_dir_iterator_next(&it);
        if (rc != EOK) {
            ext4_dir_iterator_fini(&it);
            return rc;
        }
    }

    rc = ext4_dir_iterator_fini(&it);
    if (rc != EOK)
        return rc;

    *has_children = found;

    return EOK;
}

static int ext4_link(struct ext4_mountpoint *mp, struct ext4_inode_ref *parent,
             struct ext4_inode_ref *ch, const char *n,
             uint32_t len, bool rename)
{
    /* Check maximum name length */
    if (len > EXT4_DIRECTORY_FILENAME_LEN)
        return EINVAL;

    /* Add entry to parent directory */
    int r = ext4_dir_add_entry(parent, n, len, ch);
    if (r != EOK)
        return r;

    /* Fill new dir -> add '.' and '..' entries.
     * Also newly allocated inode should have 0 link count.
     */

    bool is_dir = ext4_inode_is_type(&mp->fs.sb, ch->inode,
                   EXT4_INODE_MODE_DIRECTORY);
    if (is_dir && !rename) {

#if CONFIG_DIR_INDEX_ENABLE
        /* Initialize directory index if supported */
        if (ext4_sb_feature_com(&mp->fs.sb, EXT4_FCOM_DIR_INDEX)) {
            r = ext4_dir_dx_init(ch, parent);
            if (r != EOK)
                return r;

            ext4_inode_set_flag(ch->inode, EXT4_INODE_FLAG_INDEX);
            ch->dirty = true;
        } else
#endif
        {
            r = ext4_dir_add_entry(ch, ".", strlen("."), ch);
            if (r != EOK) {
                ext4_dir_remove_entry(parent, n, strlen(n));
                return r;
            }

            r = ext4_dir_add_entry(ch, "..", strlen(".."), parent);
            if (r != EOK) {
                ext4_dir_remove_entry(parent, n, strlen(n));
                ext4_dir_remove_entry(ch, ".", strlen("."));
                return r;
            }
        }

        /*New empty directory. Two links (. and ..) */
        ext4_inode_set_links_cnt(ch->inode, 2);
        ext4_fs_inode_links_count_inc(parent);
        ch->dirty = true;
        parent->dirty = true;
        return r;
    }
    /*
     * In case we want to rename a directory,
     * we reset the original '..' pointer.
     */
    if (is_dir) {
        bool idx;
        idx = ext4_inode_has_flag(ch->inode, EXT4_INODE_FLAG_INDEX);
        struct ext4_dir_search_result res;
        if (!idx) {
            r = ext4_dir_find_entry(&res, ch, "..", strlen(".."));
            if (r != EOK)
                return EIO;

            ext4_dir_en_set_inode(res.dentry, parent->index);
            ext4_trans_set_block_dirty(res.block.buf);
            r = ext4_dir_destroy_result(ch, &res);
            if (r != EOK)
                return r;

        } else {
#if CONFIG_DIR_INDEX_ENABLE
            r = ext4_dir_dx_reset_parent_inode(ch, parent->index);
            if (r != EOK)
                return r;

#endif
        }

        ext4_fs_inode_links_count_inc(parent);
        parent->dirty = true;
    }
    if (!rename) {
        ext4_fs_inode_links_count_inc(ch);
        ch->dirty = true;
    }

    return r;
}

static int ext4_unlink(struct ext4_mountpoint *mp,
               struct ext4_inode_ref *parent,
               struct ext4_inode_ref *child, const char *name,
               uint32_t name_len)
{
    bool has_children;
    int rc = ext4_has_children(&has_children, child);
    if (rc != EOK)
        return rc;

    /* Cannot unlink non-empty node */
    if (has_children)
        return ENOTEMPTY;

    /* Remove entry from parent directory */
    rc = ext4_dir_remove_entry(parent, name, name_len);
    if (rc != EOK)
        return rc;

    bool is_dir = ext4_inode_is_type(&mp->fs.sb, child->inode,
                     EXT4_INODE_MODE_DIRECTORY);

    /* If directory - handle links from parent */
    if (is_dir) {
        ext4_fs_inode_links_count_dec(parent);
        parent->dirty = true;
    }

    /*
     * TODO: Update timestamps of the parent
     * (when we have wall-clock time).
     *
     * ext4_inode_set_change_inode_time(parent->inode, (uint32_t) now);
     * ext4_inode_set_modification_time(parent->inode, (uint32_t) now);
     * parent->dirty = true;
     */

    /*
     * TODO: Update timestamp for inode.
     *
     * ext4_inode_set_change_inode_time(child->inode,
     *     (uint32_t) now);
     */
    if (ext4_inode_get_links_cnt(child->inode)) {
        ext4_fs_inode_links_count_dec(child);
        child->dirty = true;
    }

    return EOK;
}

/****************************************************************************/

int ext4_mount(struct ext4_blockdev *bd, const char *mount_point,
           bool read_only)
{
    int r;
    uint32_t bsize;
    struct ext4_bcache *bc;
    struct ext4_mountpoint *mp = 0;

    ext4_assert(mount_point && bd);

    size_t mp_len = strlen(mount_point);

    if (mp_len > CONFIG_EXT4_MAX_MP_NAME)
        return EINVAL;

    for (size_t i = 0; i < CONFIG_EXT4_MOUNTPOINTS_COUNT; ++i) {
        if (!s_mp[i].mounted) {
            strcpy(s_mp[i].name, mount_point);
            mp = &s_mp[i];
            break;
        }

        /*if (!strcmp(s_mp[i].name, mount_point))
            return EOK;*/
    }

    if (!mp)
        return ENOMEM;

    r = ext4_block_init(bd);
    if (r != EOK)
        return r;

    r = ext4_fs_init(&mp->fs, bd, read_only);
    if (r != EOK) {
        ext4_block_fini(bd);
        return r;
    }

    bsize = ext4_sb_get_block_size(&mp->fs.sb);
    ext4_block_set_lb_size(bd, bsize);
    bc = &mp->bc;

    r = ext4_bcache_init_dynamic(bc, CONFIG_BLOCK_DEV_CACHE_SIZE, bsize);
    if (r != EOK) {
        ext4_block_fini(bd);
        return r;
    }

    if (bsize != bc->itemsize)
        return ENOTSUP;

    /*Bind block cache to block device*/
    r = ext4_block_bind_bcache(bd, bc);
    if (r != EOK) {
        ext4_bcache_cleanup(bc);
        ext4_block_fini(bd);
        ext4_bcache_fini_dynamic(bc);
        return r;
    }

    bd->fs = &mp->fs;
    mp->mounted = 1;
    bd->journal = (void *)mp;

    ext4_cache_write_back(mp->name, true);

    return r;
}

int ext4_umount_mp(struct ext4_mountpoint *mp)
{
    int ret = ENODEV;

    if (mp && mp->mounted)
    {
        ext4_cache_write_back(mp->name, false);

        ret = ext4_fs_fini(&mp->fs);
        if (ret == EOK)
        {
            mp->mounted = 0;

            ext4_bcache_cleanup(mp->fs.bdev->bc);
            ext4_bcache_fini_dynamic(mp->fs.bdev->bc);

            ret = ext4_block_fini(mp->fs.bdev);
        }

        mp->fs.bdev->fs = NULL;
        memset(mp, 0, sizeof(struct ext4_mountpoint));
    }

    return ret;
}

int ext4_umount(const char *mount_point)
{
    int i;
    int r;
    struct ext4_mountpoint *mp = 0;

    for (i = 0; i < CONFIG_EXT4_MOUNTPOINTS_COUNT; ++i) {
        if (!strcmp(s_mp[i].name, mount_point)) {
            mp = &s_mp[i];
            break;
        }
    }

    if (!mp)
        return ENODEV;

    r = ext4_umount_mp(mp);

    return r;
}

static struct ext4_mountpoint *ext4_get_mount(const char *path)
{
    struct ext4_mountpoint *mp = NULL;
    uint32_t fspath, prefixlen;

    prefixlen = 0;
    for (size_t i = 0; i < CONFIG_EXT4_MOUNTPOINTS_COUNT; ++i) {

        if (!s_mp[i].mounted)
            continue;

        fspath = strlen(s_mp[i].name);

        if ((fspath < prefixlen) || (strncmp(s_mp[i].name, path, fspath) != 0))
            continue;

        /* check next path separator */
        if (fspath > 1 && (strlen(path) > fspath) && (path[fspath] != '/'))
            continue;
        mp = &s_mp[i];
        prefixlen = fspath;
    }
    return mp;
}

__ext4_unused
static int __ext4_journal_start(const char *mount_point)
{
    int r = EOK;
    struct ext4_mountpoint *mp = ext4_get_mount(mount_point);

    if (!mp)
        return ENOENT;

    if (mp->fs.read_only)
        return EOK;

    if (ext4_sb_feature_com(&mp->fs.sb,
                EXT4_FCOM_HAS_JOURNAL)) {
        r = jbd_get_fs(&mp->fs, &mp->jbd_fs);
        if (r != EOK)
            goto Finish;

        r = jbd_journal_start(&mp->jbd_fs, &mp->jbd_journal);
        if (r != EOK) {
            mp->jbd_fs.dirty = false;
            jbd_put_fs(&mp->jbd_fs);
            goto Finish;
        }
        mp->fs.jbd_fs = &mp->jbd_fs;
        mp->fs.jbd_journal = &mp->jbd_journal;
    }
Finish:
    return r;
}

__ext4_unused
static int __ext4_journal_stop(const char *mount_point)
{
    int r = EOK;
    struct ext4_mountpoint *mp = ext4_get_mount(mount_point);

    if (!mp)
        return ENOENT;

    if (mp->fs.read_only)
        return EOK;

    if (ext4_sb_feature_com(&mp->fs.sb,
                EXT4_FCOM_HAS_JOURNAL)) {
        r = jbd_journal_stop(&mp->jbd_journal);
        if (r != EOK) {
            mp->jbd_fs.dirty = false;
            jbd_put_fs(&mp->jbd_fs);
            mp->fs.jbd_journal = NULL;
            mp->fs.jbd_fs = NULL;
            goto Finish;
        }

        r = jbd_put_fs(&mp->jbd_fs);
        if (r != EOK) {
            mp->fs.jbd_journal = NULL;
            mp->fs.jbd_fs = NULL;
            goto Finish;
        }

        mp->fs.jbd_journal = NULL;
        mp->fs.jbd_fs = NULL;
    }
Finish:
    return r;
}

__ext4_unused
static int __ext4_recover(const char *mount_point)
{
    struct ext4_mountpoint *mp = ext4_get_mount(mount_point);
    int r = ENOTSUP;

    if (!mp)
        return ENOENT;

    EXT4_MP_LOCK(mp);
    if (ext4_sb_feature_com(&mp->fs.sb, EXT4_FCOM_HAS_JOURNAL)) {
        struct jbd_fs *jbd_fs = ext4_calloc(1, sizeof(struct jbd_fs));
        if (!jbd_fs) {
             r = ENOMEM;
             goto Finish;
        }

        r = jbd_get_fs(&mp->fs, jbd_fs);
        if (r != EOK) {
            ext4_free(jbd_fs);
            goto Finish;
        }

        r = jbd_recover(jbd_fs);
        jbd_put_fs(jbd_fs);
        ext4_free(jbd_fs);
    }
    if (r == EOK && !mp->fs.read_only) {
        uint32_t bgid;
        uint64_t free_blocks_count = 0;
        uint32_t free_inodes_count = 0;
        struct ext4_block_group_ref bg_ref;

        /* Update superblock's stats */
        for (bgid = 0;bgid < ext4_block_group_cnt(&mp->fs.sb);bgid++) {
            r = ext4_fs_get_block_group_ref(&mp->fs, bgid, &bg_ref);
            if (r != EOK)
                goto Finish;

            free_blocks_count +=
                ext4_bg_get_free_blocks_count(bg_ref.block_group,
                        &mp->fs.sb);
            free_inodes_count +=
                ext4_bg_get_free_inodes_count(bg_ref.block_group,
                        &mp->fs.sb);

            ext4_fs_put_block_group_ref(&bg_ref);
        }
        ext4_sb_set_free_blocks_cnt(&mp->fs.sb, free_blocks_count);
        ext4_set32(&mp->fs.sb, free_inodes_count, free_inodes_count);
        /* We don't need to save the superblock stats immediately. */
    }

Finish:
    EXT4_MP_UNLOCK(mp);
    return r;
}

__ext4_unused
static int __ext4_trans_start(struct ext4_mountpoint *mp)
{
    int r = EOK;

    if (mp->fs.jbd_journal && !mp->fs.curr_trans) {
        struct jbd_journal *journal = mp->fs.jbd_journal;
        struct jbd_trans *trans;
        trans = jbd_journal_new_trans(journal);
        if (!trans) {
            r = ENOMEM;
            goto Finish;
        }
        mp->fs.curr_trans = trans;
    }
Finish:
    return r;
}

__ext4_unused
static int __ext4_trans_stop(struct ext4_mountpoint *mp)
{
    int r = EOK;

    if (mp->fs.jbd_journal && mp->fs.curr_trans) {
        struct jbd_journal *journal = mp->fs.jbd_journal;
        struct jbd_trans *trans = mp->fs.curr_trans;
        r = jbd_journal_commit_trans(journal, trans);
        mp->fs.curr_trans = NULL;
    }
    return r;
}

__ext4_unused
static void __ext4_trans_abort(struct ext4_mountpoint *mp)
{
    if (mp->fs.jbd_journal && mp->fs.curr_trans) {
        struct jbd_journal *journal = mp->fs.jbd_journal;
        struct jbd_trans *trans = mp->fs.curr_trans;
        jbd_journal_free_trans(journal, trans, true);
        mp->fs.curr_trans = NULL;
    }
}

int ext4_journal_start(const char *mount_point __ext4_unused)
{
    int r = EOK;
#if CONFIG_JOURNALING_ENABLE
    r = __ext4_journal_start(mount_point);
#endif
    return r;
}

int ext4_journal_stop(const char *mount_point __ext4_unused)
{
    int r = EOK;
#if CONFIG_JOURNALING_ENABLE
    r = __ext4_journal_stop(mount_point);
#endif
    return r;
}

int ext4_recover(const char *mount_point __ext4_unused)
{
    int r = EOK;
#if CONFIG_JOURNALING_ENABLE
    r = __ext4_recover(mount_point);
#endif
    return r;
}

static int ext4_trans_start(struct ext4_mountpoint *mp __ext4_unused)
{
    int r = EOK;
#if CONFIG_JOURNALING_ENABLE
    r = __ext4_trans_start(mp);
#endif
    return r;
}

static int ext4_trans_stop(struct ext4_mountpoint *mp __ext4_unused)
{
    int r = EOK;
#if CONFIG_JOURNALING_ENABLE
    r = __ext4_trans_stop(mp);
#endif
    return r;
}

static void ext4_trans_abort(struct ext4_mountpoint *mp __ext4_unused)
{
#if CONFIG_JOURNALING_ENABLE
    __ext4_trans_abort(mp);
#endif
}


int ext4_mount_point_stats(const char *mount_point,
               struct ext4_mount_stats *stats)
{
    struct ext4_mountpoint *mp = ext4_get_mount(mount_point);

    if (!mp)
        return ENOENT;

    EXT4_MP_LOCK(mp);
    stats->inodes_count = ext4_get32(&mp->fs.sb, inodes_count);
    stats->free_inodes_count = ext4_get32(&mp->fs.sb, free_inodes_count);
    stats->blocks_count = ext4_sb_get_blocks_cnt(&mp->fs.sb);
    stats->free_blocks_count = ext4_sb_get_free_blocks_cnt(&mp->fs.sb);
    stats->block_size = ext4_sb_get_block_size(&mp->fs.sb);

    stats->block_group_count = ext4_block_group_cnt(&mp->fs.sb);
    stats->blocks_per_group = ext4_get32(&mp->fs.sb, blocks_per_group);
    stats->inodes_per_group = ext4_get32(&mp->fs.sb, inodes_per_group);

    memcpy(stats->volume_name, mp->fs.sb.volume_name, 16);
    EXT4_MP_UNLOCK(mp);

    return EOK;
}

int ext4_mount_setup_locks(const char *mount_point,
               const struct ext4_lock *locks)
{
    uint32_t i;
    struct ext4_mountpoint *mp = 0;

    for (i = 0; i < CONFIG_EXT4_MOUNTPOINTS_COUNT; ++i) {
        if (!strcmp(s_mp[i].name, mount_point)) {
            mp = &s_mp[i];
            break;
        }
    }
    if (!mp)
        return ENOENT;

    mp->os_locks = locks;
    return EOK;
}

/********************************FILE OPERATIONS*****************************/

static int ext4_path_check(const char *path, bool *is_goal)
{
    int i;

    for (i = 0; i < EXT4_DIRECTORY_FILENAME_LEN; ++i) {

        if (path[i] == '/') {
            *is_goal = false;
            return i;
        }

        if (path[i] == 0) {
            *is_goal = true;
            return i;
        }
    }

    return 0;
}

static bool ext4_parse_flags(const char *flags, uint32_t *file_flags)
{
    if (!flags)
        return false;

    if (!strcmp(flags, "r") || !strcmp(flags, "rb")) {
        *file_flags = O_RDONLY;
        return true;
    }

    if (!strcmp(flags, "w") || !strcmp(flags, "wb")) {
        *file_flags = O_WRONLY | O_CREAT | O_TRUNC;
        return true;
    }

    if (!strcmp(flags, "a") || !strcmp(flags, "ab")) {
        *file_flags = O_WRONLY | O_CREAT | O_APPEND;
        return true;
    }

    if (!strcmp(flags, "r+") || !strcmp(flags, "rb+") ||
        !strcmp(flags, "r+b")) {
        *file_flags = O_RDWR;
        return true;
    }

    if (!strcmp(flags, "w+") || !strcmp(flags, "wb+") ||
        !strcmp(flags, "w+b")) {
        *file_flags = O_RDWR | O_CREAT | O_TRUNC;
        return true;
    }

    if (!strcmp(flags, "a+") || !strcmp(flags, "ab+") ||
        !strcmp(flags, "a+b")) {
        *file_flags = O_RDWR | O_CREAT | O_APPEND;
        return true;
    }

    return false;
}

static int ext4_trunc_inode(struct ext4_mountpoint *mp,
                uint32_t index, uint64_t new_size)
{
    int r = EOK;
    struct ext4_fs *const fs = &mp->fs;
    struct ext4_inode_ref inode_ref;
    uint64_t inode_size;
    bool has_trans = mp->fs.jbd_journal && mp->fs.curr_trans;
    r = ext4_fs_get_inode_ref(fs, index, &inode_ref);
    if (r != EOK)
        return r;

    inode_size = ext4_inode_get_size(&fs->sb, inode_ref.inode);
    ext4_fs_put_inode_ref(&inode_ref);
    if (has_trans)
        ext4_trans_stop(mp);

    while (inode_size > new_size + CONFIG_MAX_TRUNCATE_SIZE) {

        inode_size -= CONFIG_MAX_TRUNCATE_SIZE;

        ext4_trans_start(mp);
        r = ext4_fs_get_inode_ref(fs, index, &inode_ref);
        if (r != EOK) {
            ext4_trans_abort(mp);
            break;
        }
        r = ext4_fs_truncate_inode(&inode_ref, inode_size);
        if (r != EOK)
            ext4_fs_put_inode_ref(&inode_ref);
        else
            r = ext4_fs_put_inode_ref(&inode_ref);

        if (r != EOK) {
            ext4_trans_abort(mp);
            goto Finish;
        } else
            ext4_trans_stop(mp);
    }

    if (inode_size > new_size) {

        inode_size = new_size;

        ext4_trans_start(mp);
        r = ext4_fs_get_inode_ref(fs, index, &inode_ref);
        if (r != EOK) {
            ext4_trans_abort(mp);
            goto Finish;
        }
        r = ext4_fs_truncate_inode(&inode_ref, inode_size);
        if (r != EOK)
            ext4_fs_put_inode_ref(&inode_ref);
        else
            r = ext4_fs_put_inode_ref(&inode_ref);

        if (r != EOK)
            ext4_trans_abort(mp);
        else
            ext4_trans_stop(mp);

    }

Finish:

    if (has_trans)
        ext4_trans_start(mp);

    return r;
}

static int ext4_trunc_dir(struct ext4_mountpoint *mp,
              struct ext4_inode_ref *parent,
              struct ext4_inode_ref *dir)
{
    int r = EOK;
    bool is_dir = ext4_inode_is_type(&mp->fs.sb, dir->inode,
            EXT4_INODE_MODE_DIRECTORY);
    uint32_t block_size = ext4_sb_get_block_size(&mp->fs.sb);
    if (!is_dir)
        return EINVAL;

#if CONFIG_DIR_INDEX_ENABLE
    /* Initialize directory index if supported */
    if (ext4_sb_feature_com(&mp->fs.sb, EXT4_FCOM_DIR_INDEX)) {
        r = ext4_dir_dx_init(dir, parent);
        if (r != EOK)
            return r;

        r = ext4_trunc_inode(mp, dir->index,
                     EXT4_DIR_DX_INIT_BCNT * block_size);
        if (r != EOK)
            return r;
    } else
#endif
    {
        r = ext4_trunc_inode(mp, dir->index, block_size);
        if (r != EOK)
            return r;
    }

    return ext4_fs_truncate_inode(dir, 0);
}

/*
 * NOTICE: if filetype is equal to EXT4_DIRENTRY_UNKNOWN,
 * any filetype of the target dir entry will be accepted.
 */
static int ext4_generic_open2(ext4_file *f, const char *path, int flags,
                  int ftype, uint32_t *parent_inode,
                  uint32_t *name_off)
{
    bool is_goal = false;
    uint32_t imode = EXT4_INODE_MODE_DIRECTORY;
    uint32_t next_inode;

    int r;
    int len;
    struct ext4_mountpoint *mp = ext4_get_mount(path);
    struct ext4_dir_search_result result;
    struct ext4_inode_ref ref;

    f->mp = 0;

    if (!mp)
        return ENOENT;

    struct ext4_fs *const fs = &mp->fs;
    struct ext4_sblock *const sb = &mp->fs.sb;

    if (fs->read_only && flags & O_CREAT)
        return EROFS;

    f->flags = flags;

    /*Skip mount point*/
    len = strlen(mp->name);
    path += len;
    if (path[0] == '/')
    {
        path += 1;
        len += 1;
    }

    if (name_off)
        *name_off = len;

    /*Load root*/
    r = ext4_fs_get_inode_ref(fs, EXT4_INODE_ROOT_INDEX, &ref);
    if (r != EOK)
        return r;

    if (parent_inode)
        *parent_inode = ref.index;

    len = ext4_path_check(path, &is_goal);
    while (1) {

        len = ext4_path_check(path, &is_goal);
        if (!len) {
            /*If root open was request.*/
            if (ftype == EXT4_DE_DIR || ftype == EXT4_DE_UNKNOWN)
                if (is_goal)
                    break;

            r = ENOENT;
            break;
        }

        r = ext4_dir_find_entry(&result, &ref, path, len);
        if (r != EOK) {

            /*Destroy last result*/
            ext4_dir_destroy_result(&ref, &result);
            if (r != ENOENT)
                break;

            if (!(f->flags & O_CREAT))
                break;

            /*O_CREAT allows create new entry*/
            struct ext4_inode_ref child_ref;
            r = ext4_fs_alloc_inode(fs, &child_ref,
                    is_goal ? ftype : EXT4_DE_DIR);

            if (r != EOK)
                break;

            ext4_fs_inode_blocks_init(fs, &child_ref);

            /*Link with root dir.*/
            r = ext4_link(mp, &ref, &child_ref, path, len, false);
            if (r != EOK) {
                /*Fail. Free new inode.*/
                ext4_fs_free_inode(&child_ref);
                /*We do not want to write new inode.
                  But block has to be released.*/
                child_ref.dirty = false;
                ext4_fs_put_inode_ref(&child_ref);
                break;
            }

            ext4_fs_put_inode_ref(&child_ref);
            continue;
        }

        if (parent_inode)
            *parent_inode = ref.index;

        next_inode = ext4_dir_en_get_inode(result.dentry);
        if (ext4_sb_feature_incom(sb, EXT4_FINCOM_FILETYPE)) {
            uint8_t t;
            t = ext4_dir_en_get_inode_type(sb, result.dentry);
            imode = ext4_fs_correspond_inode_mode(t);
        } else {
            struct ext4_inode_ref child_ref;
            r = ext4_fs_get_inode_ref(fs, next_inode, &child_ref);
            if (r != EOK)
                break;

            imode = ext4_inode_type(sb, child_ref.inode);
            ext4_fs_put_inode_ref(&child_ref);
        }

        r = ext4_dir_destroy_result(&ref, &result);
        if (r != EOK)
            break;

        /*If expected file error*/
        if (imode != EXT4_INODE_MODE_DIRECTORY && !is_goal) {
            r = ENOENT;
            break;
        }
        if (ftype != EXT4_DE_UNKNOWN) {
            bool df = imode != ext4_fs_correspond_inode_mode(ftype);
            if (df && is_goal) {
                r = ENOENT;
                break;
            }
        }

        r = ext4_fs_put_inode_ref(&ref);
        if (r != EOK)
            break;

        r = ext4_fs_get_inode_ref(fs, next_inode, &ref);
        if (r != EOK)
            break;

        if (is_goal)
            break;

        path += len + 1;

        if (name_off)
            *name_off += len + 1;
    }

    if (r != EOK) {
        ext4_fs_put_inode_ref(&ref);
        return r;
    }

    if (is_goal) {

        if ((f->flags & O_TRUNC) && (imode == EXT4_INODE_MODE_FILE)) {
            r = ext4_trunc_inode(mp, ref.index, 0);
            if (r != EOK) {
                ext4_fs_put_inode_ref(&ref);
                return r;
            }
        }

        f->mp = mp;
        f->fsize = ext4_inode_get_size(sb, ref.inode);
        f->inode = ref.index;
        f->fpos = 0;

        if (f->flags & O_APPEND)
            f->fpos = f->fsize;
    }

    return ext4_fs_put_inode_ref(&ref);
}

/****************************************************************************/

static int ext4_generic_open(ext4_file *f, const char *path, const char *flags,
                 bool file_expect, uint32_t *parent_inode,
                 uint32_t *name_off)
{
    uint32_t iflags;
    int filetype;
    int r;
    struct ext4_mountpoint *mp = ext4_get_mount(path);

    if (ext4_parse_flags(flags, &iflags) == false)
        return EINVAL;

    if (file_expect == true)
        filetype = EXT4_DE_REG_FILE;
    else
        filetype = EXT4_DE_DIR;

    if (iflags & O_CREAT)
        ext4_trans_start(mp);

    r = ext4_generic_open2(f, path, iflags, filetype, parent_inode,
                name_off);

    if (iflags & O_CREAT) {
        if (r == EOK)
            ext4_trans_stop(mp);
        else
            ext4_trans_abort(mp);
    }

    return r;
}

static int ext4_create_hardlink(const char *path,
        struct ext4_inode_ref *child_ref, bool rename)
{
    bool is_goal = false;
    uint32_t inode_mode = EXT4_INODE_MODE_DIRECTORY;
    uint32_t next_inode;

    int r;
    int len;
    struct ext4_mountpoint *mp = ext4_get_mount(path);
    struct ext4_dir_search_result result;
    struct ext4_inode_ref ref;

    if (!mp)
        return ENOENT;

    struct ext4_fs *const fs = &mp->fs;
    struct ext4_sblock *const sb = &mp->fs.sb;

    /*Skip mount point*/
    path += strlen(mp->name);
    if (path[0] == '/')
    {
        path += 1;
    }
    /*Load root*/
    r = ext4_fs_get_inode_ref(fs, EXT4_INODE_ROOT_INDEX, &ref);
    if (r != EOK)
        return r;

    len = ext4_path_check(path, &is_goal);
    while (1) {

        len = ext4_path_check(path, &is_goal);
        if (!len) {
            /*If root open was request.*/
            r = is_goal ? EINVAL : ENOENT;
            break;
        }

        r = ext4_dir_find_entry(&result, &ref, path, len);
        if (r != EOK) {

            /*Destroy last result*/
            ext4_dir_destroy_result(&ref, &result);

            if (r != ENOENT || !is_goal)
                break;

            /*Link with root dir.*/
            r = ext4_link(mp, &ref, child_ref, path, len, rename);
            break;
        } else if (r == EOK && is_goal) {
            /*Destroy last result*/
            ext4_dir_destroy_result(&ref, &result);
            r = EEXIST;
            break;
        }

        next_inode = result.dentry->inode;
        if (ext4_sb_feature_incom(sb, EXT4_FINCOM_FILETYPE)) {
            uint8_t t;
            t = ext4_dir_en_get_inode_type(sb, result.dentry);
            inode_mode = ext4_fs_correspond_inode_mode(t);
        } else {
            struct ext4_inode_ref child_ref;
            r = ext4_fs_get_inode_ref(fs, next_inode, &child_ref);
            if (r != EOK)
                break;

            inode_mode = ext4_inode_type(sb, child_ref.inode);
            ext4_fs_put_inode_ref(&child_ref);
        }

        r = ext4_dir_destroy_result(&ref, &result);
        if (r != EOK)
            break;

        if (inode_mode != EXT4_INODE_MODE_DIRECTORY) {
            r = is_goal ? EEXIST : ENOENT;
            break;
        }

        r = ext4_fs_put_inode_ref(&ref);
        if (r != EOK)
            break;

        r = ext4_fs_get_inode_ref(fs, next_inode, &ref);
        if (r != EOK)
            break;

        if (is_goal)
            break;

        path += len + 1;
    };

    if (r != EOK) {
        ext4_fs_put_inode_ref(&ref);
        return r;
    }

    r = ext4_fs_put_inode_ref(&ref);
    return r;
}

static int ext4_remove_orig_reference(const char *path, uint32_t name_off,
                      struct ext4_inode_ref *parent_ref,
                      struct ext4_inode_ref *child_ref)
{
    bool is_goal;
    int r;
    int len;
    struct ext4_mountpoint *mp = ext4_get_mount(path);

    if (!mp)
        return ENOENT;

    /*Set path*/
    path += name_off;

    len = ext4_path_check(path, &is_goal);

    /* Remove entry from parent directory */
    r = ext4_dir_remove_entry(parent_ref, path, len);
    if (r != EOK)
        goto Finish;

    if (ext4_inode_is_type(&mp->fs.sb, child_ref->inode,
                   EXT4_INODE_MODE_DIRECTORY)) {
        ext4_fs_inode_links_count_dec(parent_ref);
        parent_ref->dirty = true;
    }
Finish:
    return r;
}

int ext4_flink(const char *path, const char *hardlink_path)
{
    int r;
    ext4_file f;
    uint32_t name_off;
    bool child_loaded = false;
    uint32_t parent_inode, child_inode;
    struct ext4_mountpoint *mp = ext4_get_mount(path);
    struct ext4_mountpoint *target_mp = ext4_get_mount(hardlink_path);
    struct ext4_inode_ref child_ref;

    if (!mp)
        return ENOENT;

    if (mp->fs.read_only)
        return EROFS;

    /* Will that happen? Anyway return EINVAL for such case. */
    if (mp != target_mp)
        return EINVAL;

    EXT4_MP_LOCK(mp);
    r = ext4_generic_open2(&f, path, O_RDONLY, EXT4_DE_UNKNOWN,
                   &parent_inode, &name_off);
    if (r != EOK) {
        EXT4_MP_UNLOCK(mp);
        return r;
    }

    child_inode = f.inode;
    ext4_fclose(&f);
    ext4_trans_start(mp);

    /*We have file to unlink. Load it.*/
    r = ext4_fs_get_inode_ref(&mp->fs, child_inode, &child_ref);
    if (r != EOK)
        goto Finish;

    child_loaded = true;

    /* Creating hardlink for directory is not allowed. */
    if (ext4_inode_is_type(&mp->fs.sb, child_ref.inode,
                   EXT4_INODE_MODE_DIRECTORY)) {
        r = EINVAL;
        goto Finish;
    }

    r = ext4_create_hardlink(hardlink_path, &child_ref, false);

Finish:
    if (child_loaded)
        ext4_fs_put_inode_ref(&child_ref);

    if (r != EOK)
        ext4_trans_abort(mp);
    else
        ext4_trans_stop(mp);

    EXT4_MP_UNLOCK(mp);
    return r;

}

int ext4_frename(const char *path, const char *new_path)
{
    int r;
    ext4_file f;
    uint32_t name_off;
    bool parent_loaded = false, child_loaded = false;
    uint32_t parent_inode, child_inode;
    struct ext4_mountpoint *mp = ext4_get_mount(path);
    struct ext4_inode_ref child_ref, parent_ref;

    if (!mp)
        return ENOENT;

    if (mp->fs.read_only)
        return EROFS;

    EXT4_MP_LOCK(mp);

    r = ext4_generic_open2(&f, path, O_RDONLY, EXT4_DE_UNKNOWN,
                &parent_inode, &name_off);
    if (r != EOK) {
        EXT4_MP_UNLOCK(mp);
        return r;
    }

    child_inode = f.inode;
    ext4_fclose(&f);
    ext4_trans_start(mp);

    /*Load parent*/
    r = ext4_fs_get_inode_ref(&mp->fs, parent_inode, &parent_ref);
    if (r != EOK)
        goto Finish;

    parent_loaded = true;

    /*We have file to unlink. Load it.*/
    r = ext4_fs_get_inode_ref(&mp->fs, child_inode, &child_ref);
    if (r != EOK)
        goto Finish;

    child_loaded = true;

    r = ext4_create_hardlink(new_path, &child_ref, true);
    if (r != EOK)
        goto Finish;

    r = ext4_remove_orig_reference(path, name_off, &parent_ref, &child_ref);
    if (r != EOK)
        goto Finish;

Finish:
    if (parent_loaded)
        ext4_fs_put_inode_ref(&parent_ref);

    if (child_loaded)
        ext4_fs_put_inode_ref(&child_ref);

    if (r != EOK)
        ext4_trans_abort(mp);
    else
        ext4_trans_stop(mp);

    EXT4_MP_UNLOCK(mp);
    return r;

}

/****************************************************************************/

int ext4_get_sblock(const char *mount_point, struct ext4_sblock **sb)
{
    struct ext4_mountpoint *mp = ext4_get_mount(mount_point);

    if (!mp)
        return ENOENT;

    *sb = &mp->fs.sb;
    return EOK;
}

int ext4_cache_write_back(const char *path, bool on)
{
    struct ext4_mountpoint *mp = ext4_get_mount(path);
    int ret;

    if (!mp)
        return ENOENT;

    EXT4_MP_LOCK(mp);
    ret = ext4_block_cache_write_back(mp->fs.bdev, on);
    EXT4_MP_UNLOCK(mp);
    return ret;
}

int ext4_cache_flush(const char *path)
{
    struct ext4_mountpoint *mp = ext4_get_mount(path);
    int ret;

    if (!mp)
        return ENOENT;

    EXT4_MP_LOCK(mp);
    ret = ext4_block_cache_flush(mp->fs.bdev);
    EXT4_MP_UNLOCK(mp);
    return ret;
}

int ext4_fremove(const char *path)
{
    ext4_file f;
    uint32_t parent_inode;
    uint32_t child_inode;
    uint32_t name_off;
    bool is_goal;
    int r;
    int len;
    struct ext4_inode_ref child;
    struct ext4_inode_ref parent;
    struct ext4_mountpoint *mp = ext4_get_mount(path);

    if (!mp)
        return ENOENT;

    if (mp->fs.read_only)
        return EROFS;

    EXT4_MP_LOCK(mp);
    r = ext4_generic_open2(&f, path, O_RDONLY, EXT4_DE_UNKNOWN,
                   &parent_inode, &name_off);
    if (r != EOK) {
        EXT4_MP_UNLOCK(mp);
        return r;
    }

    child_inode = f.inode;
    ext4_fclose(&f);
    ext4_trans_start(mp);

    /*Load parent*/
    r = ext4_fs_get_inode_ref(&mp->fs, parent_inode, &parent);
    if (r != EOK) {
        ext4_trans_abort(mp);
        EXT4_MP_UNLOCK(mp);
        return r;
    }

    /*We have file to delete. Load it.*/
    r = ext4_fs_get_inode_ref(&mp->fs, child_inode, &child);
    if (r != EOK) {
        ext4_fs_put_inode_ref(&parent);
        ext4_trans_abort(mp);
        EXT4_MP_UNLOCK(mp);
        return r;
    }
    /* We do not allow opening files here. */
    if (ext4_inode_type(&mp->fs.sb, child.inode) ==
        EXT4_INODE_MODE_DIRECTORY) {
        ext4_fs_put_inode_ref(&parent);
        ext4_fs_put_inode_ref(&child);
        ext4_trans_abort(mp);
        EXT4_MP_UNLOCK(mp);
        return r;
    }

    /*Link count will be zero, the inode should be freed. */
    if (ext4_inode_get_links_cnt(child.inode) == 1) {
        ext4_block_cache_write_back(mp->fs.bdev, 1);
        r = ext4_trunc_inode(mp, child.index, 0);
        if (r != EOK) {
            ext4_fs_put_inode_ref(&parent);
            ext4_fs_put_inode_ref(&child);
            ext4_trans_abort(mp);
            EXT4_MP_UNLOCK(mp);
            return r;
        }
        ext4_block_cache_write_back(mp->fs.bdev, 0);
    }

    /*Set path*/
    path += name_off;
    if (path[0] == '/')
    {
        path += 1;
    }

    len = ext4_path_check(path, &is_goal);

    /*Unlink from parent*/
    r = ext4_unlink(mp, &parent, &child, path, len);
    if (r != EOK)
        goto Finish;

    /*Link count is zero, the inode should be freed. */
    if (!ext4_inode_get_links_cnt(child.inode)) {
        ext4_inode_set_del_time(child.inode, -1L);

        r = ext4_fs_free_inode(&child);
        if (r != EOK)
            goto Finish;
    }

Finish:
    ext4_fs_put_inode_ref(&child);
    ext4_fs_put_inode_ref(&parent);

    if (r != EOK)
        ext4_trans_abort(mp);
    else
        ext4_trans_stop(mp);

    EXT4_MP_UNLOCK(mp);
    return r;
}

int ext4_fopen(ext4_file *file, const char *path, const char *flags)
{
    struct ext4_mountpoint *mp = ext4_get_mount(path);
    int r;

    if (!mp)
        return ENOENT;

    EXT4_MP_LOCK(mp);

    ext4_block_cache_write_back(mp->fs.bdev, 1);
    r = ext4_generic_open(file, path, flags, true, 0, 0);
    ext4_block_cache_write_back(mp->fs.bdev, 0);

    EXT4_MP_UNLOCK(mp);
    return r;
}

int ext4_fopen2(ext4_file *file, const char *path, int flags)
{
    struct ext4_mountpoint *mp = ext4_get_mount(path);
    int r;
    int filetype;

    if (!mp)
        return ENOENT;

    filetype = EXT4_DE_REG_FILE;

    EXT4_MP_LOCK(mp);
    ext4_block_cache_write_back(mp->fs.bdev, 1);

    if (flags & O_CREAT)
        ext4_trans_start(mp);

    r = ext4_generic_open2(file, path, flags, filetype, NULL, NULL);

    if (flags & O_CREAT) {
        if (r == EOK)
            ext4_trans_stop(mp);
        else
            ext4_trans_abort(mp);
    }

    ext4_block_cache_write_back(mp->fs.bdev, 0);
    EXT4_MP_UNLOCK(mp);

    return r;
}

int ext4_fclose(ext4_file *file)
{
    ext4_assert(file && file->mp);

    EXT4_MP_LOCK(file->mp);
    ext4_block_cache_flush(file->mp->fs.bdev);
    EXT4_MP_UNLOCK(file->mp);

    file->mp = 0;
    file->flags = 0;
    file->inode = 0;
    file->fpos = file->fsize = 0;

    return EOK;
}

static int ext4_ftruncate_no_lock(ext4_file *file, uint64_t size)
{
    struct ext4_inode_ref ref;
    int r;


    r = ext4_fs_get_inode_ref(&file->mp->fs, file->inode, &ref);
    if (r != EOK) {
        EXT4_MP_UNLOCK(file->mp);
        return r;
    }

    /*Sync file size*/
    file->fsize = ext4_inode_get_size(&file->mp->fs.sb, ref.inode);
    if (file->fsize <= size) {
        r = EOK;
        goto Finish;
    }

    /*Start write back cache mode.*/
    r = ext4_block_cache_write_back(file->mp->fs.bdev, 1);
    if (r != EOK)
        goto Finish;

    r = ext4_trunc_inode(file->mp, ref.index, size);
    if (r != EOK)
        goto Finish;

    file->fsize = size;
    if (file->fpos > size)
        file->fpos = size;

    /*Stop write back cache mode*/
    ext4_block_cache_write_back(file->mp->fs.bdev, 0);

    if (r != EOK)
        goto Finish;

Finish:
    ext4_fs_put_inode_ref(&ref);
    return r;

}

int ext4_ftruncate(ext4_file *f, uint64_t size)
{
    int r;
    ext4_assert(f && f->mp);

    if (f->mp->fs.read_only)
        return EROFS;

    if (f->flags & O_RDONLY)
        return EPERM;

    EXT4_MP_LOCK(f->mp);

    ext4_trans_start(f->mp);
    r = ext4_ftruncate_no_lock(f, size);
    if (r != EOK)
        ext4_trans_abort(f->mp);
    else
        ext4_trans_stop(f->mp);

    EXT4_MP_UNLOCK(f->mp);
    return r;
}

int ext4_fread(ext4_file *file, void *buf, size_t size, size_t *rcnt)
{
    uint32_t unalg;
    uint32_t iblock_idx;
    uint32_t iblock_last;
    uint32_t block_size;

    ext4_fsblk_t fblock;
    ext4_fsblk_t fblock_start;
    uint32_t fblock_count;

    uint8_t *u8_buf = buf;
    int r;
    struct ext4_inode_ref ref;

    ext4_assert(file && file->mp);

    if (file->flags & O_WRONLY)
        return EPERM;

    if (!size)
        return EOK;

    EXT4_MP_LOCK(file->mp);

    struct ext4_fs *const fs = &file->mp->fs;
    struct ext4_sblock *const sb = &file->mp->fs.sb;

    if (rcnt)
        *rcnt = 0;

    r = ext4_fs_get_inode_ref(fs, file->inode, &ref);
    if (r != EOK) {
        EXT4_MP_UNLOCK(file->mp);
        return r;
    }

    /*Sync file size*/
    file->fsize = ext4_inode_get_size(sb, ref.inode);

    block_size = ext4_sb_get_block_size(sb);
    size = ((uint64_t)size > (file->fsize - file->fpos))
        ? ((size_t)(file->fsize - file->fpos)) : size;

    iblock_idx = (uint32_t)((file->fpos) / block_size);
    iblock_last = (uint32_t)((file->fpos + size) / block_size);
    unalg = (file->fpos) % block_size;
    /*If the size of symlink is smaller than 60 bytes*/
    bool softlink;
    softlink = ext4_inode_is_type(sb, ref.inode, EXT4_INODE_MODE_SOFTLINK);
    if (softlink && file->fsize < sizeof(ref.inode->blocks)
             && !ext4_inode_get_blocks_count(sb, ref.inode)) {

        char *content = (char *)ref.inode->blocks;
        if (file->fpos < file->fsize) {
            size_t len = size;
            if (unalg + size > (uint32_t)file->fsize)
                len = (uint32_t)file->fsize - unalg;
            memcpy(buf, content + unalg, len);
            if (rcnt)
                *rcnt = len;

        }

        r = EOK;
        goto Finish;
    }

    if (unalg) {
        size_t len =  size;
        if (size > (block_size - unalg))
            len = block_size - unalg;

        r = ext4_fs_get_inode_dblk_idx(&ref, iblock_idx, &fblock, true);
        if (r != EOK)
            goto Finish;

        /* Do we get an unwritten range? */
        if (fblock != 0) {
            uint64_t off = fblock * block_size + unalg;
            r = ext4_block_readbytes(file->mp->fs.bdev, off, u8_buf, len);
            if (r != EOK)
                goto Finish;

        } else {
            /* Yes, we do. */
            memset(u8_buf, 0, len);
        }

        u8_buf += len;
        size -= len;
        file->fpos += len;

        if (rcnt)
            *rcnt += len;

        iblock_idx++;
    }

    fblock_start = 0;
    fblock_count = 0;
    while (size >= block_size) {
        while (iblock_idx < iblock_last) {
            r = ext4_fs_get_inode_dblk_idx(&ref, iblock_idx,
                               &fblock, true);
            if (r != EOK)
                goto Finish;

            iblock_idx++;

            if (!fblock_start)
                fblock_start = fblock;

            if ((fblock_start + fblock_count) != fblock)
                break;

            fblock_count++;
        }

        if (fblock_start == 0) {
            memset(u8_buf, 0, block_size * fblock_count);
            r = EOK;
        } else {
            r = ext4_blocks_get_direct(file->mp->fs.bdev, u8_buf, fblock_start,
                       fblock_count);
        }

        if (r != EOK)
            goto Finish;

        size -= block_size * fblock_count;
        u8_buf += block_size * fblock_count;
        file->fpos += block_size * fblock_count;

        if (rcnt)
            *rcnt += block_size * fblock_count;

        fblock_start = fblock;
        fblock_count = 1;
    }

    if (size) {
        uint64_t off;
        r = ext4_fs_get_inode_dblk_idx(&ref, iblock_idx, &fblock, true);
        if (r != EOK)
            goto Finish;

        off = fblock * block_size;
        r = ext4_block_readbytes(file->mp->fs.bdev, off, u8_buf, size);
        if (r != EOK)
            goto Finish;

        file->fpos += size;

        if (rcnt)
            *rcnt += size;
    }


Finish:
    ext4_fs_put_inode_ref(&ref);
    EXT4_MP_UNLOCK(file->mp);
    return r;
}

int ext4_fwrite(ext4_file *file, const void *buf, size_t size, size_t *wcnt)
{
    uint32_t unalg;
    uint32_t iblk_idx;
    uint32_t iblock_last;
    uint32_t ifile_blocks;
    uint32_t block_size;

    uint32_t fblock_count;
    ext4_fsblk_t fblk;
    ext4_fsblk_t fblock_start;

    struct ext4_inode_ref ref;
    const uint8_t *u8_buf = buf;
    int r, rr = EOK;

    ext4_assert(file && file->mp);

    if (file->mp->fs.read_only)
        return EROFS;

    if (file->flags & O_RDONLY)
        return EPERM;

    if (!size)
        return EOK;

    EXT4_MP_LOCK(file->mp);
    ext4_trans_start(file->mp);

    struct ext4_fs *const fs = &file->mp->fs;
    struct ext4_sblock *const sb = &file->mp->fs.sb;

    if (wcnt)
        *wcnt = 0;

    r = ext4_fs_get_inode_ref(fs, file->inode, &ref);
    if (r != EOK) {
        ext4_trans_abort(file->mp);
        EXT4_MP_UNLOCK(file->mp);
        return r;
    }

    /*Sync file size*/
    file->fsize = ext4_inode_get_size(sb, ref.inode);
    if (file->fpos > file->fsize) {
        file->fsize = file->fpos;
        ext4_inode_set_size(ref.inode, file->fsize);
        ref.dirty = true;
    }
    block_size = ext4_sb_get_block_size(sb);

    iblock_last = (uint32_t)((file->fpos + size) / block_size);
    iblk_idx = (uint32_t)(file->fpos / block_size);
    ifile_blocks = (uint32_t)((file->fsize + block_size - 1) / block_size);

    unalg = (file->fpos) % block_size;
    if (unalg) {
        size_t len =  size;
        uint64_t off;
        if (size > (block_size - unalg))
            len = block_size - unalg;

        r = ext4_fs_init_inode_dblk_idx(&ref, iblk_idx, &fblk);
        if (r != EOK)
            goto Finish;

        off = fblk * block_size + unalg;
        r = ext4_block_writebytes(file->mp->fs.bdev, off, u8_buf, len);
        if (r != EOK)
            goto Finish;

        u8_buf += len;
        size -= len;
        file->fpos += len;

        if (wcnt)
            *wcnt += len;

        iblk_idx++;
    }

    /*Start write back cache mode.*/
    r = ext4_block_cache_write_back(file->mp->fs.bdev, 1);
    if (r != EOK)
        goto Finish;

    fblock_start = 0;
    fblock_count = 0;
    while (size >= block_size) {

        while (iblk_idx < iblock_last) {
            if (iblk_idx < ifile_blocks) {
                r = ext4_fs_init_inode_dblk_idx(&ref, iblk_idx,
                                &fblk);
                if (r != EOK)
                    goto Finish;
            } else {
                rr = ext4_fs_append_inode_dblk(&ref, &fblk,
                                   &iblk_idx);
                if (rr != EOK) {
                    /* Unable to append more blocks. But
                     * some block might be allocated already
                     * */
                    break;
                }
            }

            iblk_idx++;

            if (!fblock_start) {
                fblock_start = fblk;
            }

            if ((fblock_start + fblock_count) != fblk)
                break;

            fblock_count++;
        }

        r = ext4_blocks_set_direct(file->mp->fs.bdev, u8_buf, fblock_start,
                       fblock_count);
        if (r != EOK)
            break;

        size -= block_size * fblock_count;
        u8_buf += block_size * fblock_count;
        file->fpos += block_size * fblock_count;

        if (wcnt)
            *wcnt += block_size * fblock_count;

        fblock_start = fblk;
        fblock_count = 1;

        if (rr != EOK) {
            /*ext4_fs_append_inode_block has failed and no
             * more blocks might be written. But node size
             * should be updated.*/
            r = rr;
            goto out_fsize;
        }
    }

    /*Stop write back cache mode*/
    ext4_block_cache_write_back(file->mp->fs.bdev, 0);

    if (r != EOK)
        goto Finish;

    if (size) {
        uint64_t off;
        if (iblk_idx < ifile_blocks) {
            r = ext4_fs_init_inode_dblk_idx(&ref, iblk_idx, &fblk);
            if (r != EOK)
                goto Finish;
        } else {
            r = ext4_fs_append_inode_dblk(&ref, &fblk, &iblk_idx);
            if (r != EOK)
                /*Node size sholud be updated.*/
                goto out_fsize;
        }

        off = fblk * block_size;
        r = ext4_block_writebytes(file->mp->fs.bdev, off, u8_buf, size);
        if (r != EOK)
            goto Finish;

        file->fpos += size;

        if (wcnt)
            *wcnt += size;
    }

out_fsize:
    if (file->fpos > file->fsize) {
        file->fsize = file->fpos;
        ext4_inode_set_size(ref.inode, file->fsize);
        ref.dirty = true;
    }

Finish:
    r = ext4_fs_put_inode_ref(&ref);

    if (r != EOK)
        ext4_trans_abort(file->mp);
    else
        ext4_trans_stop(file->mp);

    EXT4_MP_UNLOCK(file->mp);
    return r;
}

int ext4_fseek(ext4_file *file, int64_t offset, uint32_t origin)
{
    int ret = EOK;
    off_t new_offset = 0;

    switch (origin) {
    case SEEK_SET:
        new_offset = offset;
        break;

    case SEEK_CUR:
        new_offset = file->fpos + offset;
        break;

    case SEEK_END:
        new_offset = file->fsize + offset;
        break;
    }

    if (new_offset < 0) ret = EINVAL;
    else
    {
        file->fpos = new_offset;
    }

    return ret;
}

uint64_t ext4_ftell(ext4_file *file)
{
    return file->fpos;
}

uint64_t ext4_fsize(ext4_file *file)
{
    return file->fsize;
}


static int ext4_trans_get_inode_ref(const char *path,
                    struct ext4_mountpoint *mp,
                    struct ext4_inode_ref *inode_ref)
{
    int r;
    ext4_file f;

    r = ext4_generic_open2(&f, path, O_RDONLY, EXT4_DE_UNKNOWN, NULL, NULL);
    if (r != EOK)
        return r;

    ext4_trans_start(mp);

    r = ext4_fs_get_inode_ref(&mp->fs, f.inode, inode_ref);
    if (r != EOK) {
        ext4_trans_abort(mp);
        return r;
    }

    ext4_bcache_inc_read_ref(inode_ref->block.buf);

    return r;
}

static int ext4_trans_put_inode_ref(struct ext4_mountpoint *mp,
                    struct ext4_inode_ref *inode_ref)
{
    int r;

    ext4_bcache_dec_read_ref(inode_ref->block.buf);
    r = ext4_fs_put_inode_ref(inode_ref);
    if (r != EOK)
        ext4_trans_abort(mp);
    else
        ext4_trans_stop(mp);

    return r;
}


int ext4_raw_inode_fill(const char *path, uint32_t *ret_ino,
            struct ext4_inode *inode)
{
    int r;
    ext4_file f;
    struct ext4_inode_ref inode_ref;
    struct ext4_mountpoint *mp = ext4_get_mount(path);

    if (!mp)
        return ENOENT;

    EXT4_MP_LOCK(mp);

    r = ext4_generic_open2(&f, path, O_RDONLY, EXT4_DE_UNKNOWN, NULL, NULL);
    if (r != EOK) {
        EXT4_MP_UNLOCK(mp);
        return r;
    }

    /*Load parent*/
    r = ext4_fs_get_inode_ref(&mp->fs, f.inode, &inode_ref);
    if (r != EOK) {
        EXT4_MP_UNLOCK(mp);
        return r;
    }

    if (ret_ino)
        *ret_ino = f.inode;

    memcpy(inode, inode_ref.inode, sizeof(struct ext4_inode));
    ext4_fs_put_inode_ref(&inode_ref);
    EXT4_MP_UNLOCK(mp);

    return r;
}

int ext4_inode_exist(const char *path, int type)
{
    int r;
    ext4_file f;
    struct ext4_mountpoint *mp = ext4_get_mount(path);

    if (!mp)
        return ENOENT;

    EXT4_MP_LOCK(mp);
    r = ext4_generic_open2(&f, path, O_RDONLY, type, NULL, NULL);
    EXT4_MP_UNLOCK(mp);

    return r;
}

void* ext4_get_inode_ref(const char *path, struct ext4_inode_ref *ref)
{
    int ret;
    struct ext4_mountpoint *mp = ext4_get_mount(path);

    if (!mp)
        return NULL;

    EXT4_MP_LOCK(mp);
    ret = ext4_trans_get_inode_ref(path, mp, ref);
    EXT4_MP_UNLOCK(mp);

    if (ret != EOK) mp = NULL;

    return mp;
}

int ext4_put_inode_ref(struct ext4_mountpoint *mp, struct ext4_inode_ref *ref)
{
    int ret = EOK;

    EXT4_MP_LOCK(mp);
    ret = ext4_trans_put_inode_ref(mp, ref);
    EXT4_MP_UNLOCK(mp);

    return ret;
}

int ext4_mode_set(const char *path, uint32_t mode)
{
    int r;
    uint32_t orig_mode;
    struct ext4_inode_ref inode_ref;
    struct ext4_mountpoint *mp = ext4_get_mount(path);

    if (!mp)
        return ENOENT;

    if (mp->fs.read_only)
        return EROFS;

    EXT4_MP_LOCK(mp);

    r = ext4_trans_get_inode_ref(path, mp, &inode_ref);
    if (r != EOK)
        goto Finish;

    orig_mode = ext4_inode_get_mode(&mp->fs.sb, inode_ref.inode);
    orig_mode &= ~0xFFF;
    orig_mode |= mode & 0xFFF;
    ext4_inode_set_mode(&mp->fs.sb, inode_ref.inode, orig_mode);

    inode_ref.dirty = true;
    r = ext4_trans_put_inode_ref(mp, &inode_ref);

    Finish:
    EXT4_MP_UNLOCK(mp);

    return r;
}

int ext4_owner_set(const char *path, uint32_t uid, uint32_t gid)
{
    int r;
    struct ext4_inode_ref inode_ref;
    struct ext4_mountpoint *mp = ext4_get_mount(path);

    if (!mp)
        return ENOENT;

    if (mp->fs.read_only)
        return EROFS;

    EXT4_MP_LOCK(mp);

    r = ext4_trans_get_inode_ref(path, mp, &inode_ref);
    if (r != EOK)
        goto Finish;

    ext4_inode_set_uid(inode_ref.inode, uid);
    ext4_inode_set_gid(inode_ref.inode, gid);

    inode_ref.dirty = true;
    r = ext4_trans_put_inode_ref(mp, &inode_ref);

    Finish:
    EXT4_MP_UNLOCK(mp);

    return r;
}

int ext4_mode_get(const char *path, uint32_t *mode)
{
    struct ext4_inode_ref inode_ref;
    struct ext4_mountpoint *mp = ext4_get_mount(path);
    ext4_file f;
    int r;

    if (!mp)
        return ENOENT;

    EXT4_MP_LOCK(mp);

    r = ext4_generic_open2(&f, path, O_RDONLY, EXT4_DE_UNKNOWN, NULL, NULL);
    if (r != EOK)
        goto Finish;

    r = ext4_fs_get_inode_ref(&mp->fs, f.inode, &inode_ref);
    if (r != EOK)
        goto Finish;

    *mode = ext4_inode_get_mode(&mp->fs.sb, inode_ref.inode);
    r = ext4_fs_put_inode_ref(&inode_ref);

    Finish:
    EXT4_MP_UNLOCK(mp);

    return r;
}

int ext4_owner_get(const char *path, uint32_t *uid, uint32_t *gid)
{
    struct ext4_inode_ref inode_ref;
    struct ext4_mountpoint *mp = ext4_get_mount(path);
    ext4_file f;
    int r;

    if (!mp)
        return ENOENT;

    EXT4_MP_LOCK(mp);

    r = ext4_generic_open2(&f, path, O_RDONLY, EXT4_DE_UNKNOWN, NULL, NULL);
    if (r != EOK)
        goto Finish;

    r = ext4_fs_get_inode_ref(&mp->fs, f.inode, &inode_ref);
    if (r != EOK)
        goto Finish;

    *uid = ext4_inode_get_uid(inode_ref.inode);
    *gid = ext4_inode_get_gid(inode_ref.inode);
    r = ext4_fs_put_inode_ref(&inode_ref);

    Finish:
    EXT4_MP_UNLOCK(mp);

    return r;
}

int ext4_atime_set(const char *path, uint32_t atime)
{
    struct ext4_inode_ref inode_ref;
    struct ext4_mountpoint *mp = ext4_get_mount(path);
    int r;

    if (!mp)
        return ENOENT;

    if (mp->fs.read_only)
        return EROFS;

    EXT4_MP_LOCK(mp);

    r = ext4_trans_get_inode_ref(path, mp, &inode_ref);
    if (r != EOK)
        goto Finish;

    ext4_inode_set_access_time(inode_ref.inode, atime);
    inode_ref.dirty = true;
    r = ext4_trans_put_inode_ref(mp, &inode_ref);

    Finish:
    EXT4_MP_UNLOCK(mp);

    return r;
}

int ext4_mtime_set(const char *path, uint32_t mtime)
{
    struct ext4_inode_ref inode_ref;
    struct ext4_mountpoint *mp = ext4_get_mount(path);
    int r;

    if (!mp)
        return ENOENT;

    if (mp->fs.read_only)
        return EROFS;

    EXT4_MP_LOCK(mp);

    r = ext4_trans_get_inode_ref(path, mp, &inode_ref);
    if (r != EOK)
        goto Finish;

    ext4_inode_set_modif_time(inode_ref.inode, mtime);
    inode_ref.dirty = true;
    r = ext4_trans_put_inode_ref(mp, &inode_ref);

    Finish:
    EXT4_MP_UNLOCK(mp);

    return r;
}

int ext4_ctime_set(const char *path, uint32_t ctime)
{
    struct ext4_inode_ref inode_ref;
    struct ext4_mountpoint *mp = ext4_get_mount(path);
    int r;

    if (!mp)
        return ENOENT;

    if (mp->fs.read_only)
        return EROFS;

    EXT4_MP_LOCK(mp);

    r = ext4_trans_get_inode_ref(path, mp, &inode_ref);
    if (r != EOK)
        goto Finish;

    ext4_inode_set_change_inode_time(inode_ref.inode, ctime);
    inode_ref.dirty = true;
    r = ext4_trans_put_inode_ref(mp, &inode_ref);

    Finish:
    EXT4_MP_UNLOCK(mp);

    return r;
}

int ext4_atime_get(const char *path, uint32_t *atime)
{
    struct ext4_inode_ref inode_ref;
    struct ext4_mountpoint *mp = ext4_get_mount(path);
    ext4_file f;
    int r;

    if (!mp)
        return ENOENT;

    EXT4_MP_LOCK(mp);

    r = ext4_generic_open2(&f, path, O_RDONLY, EXT4_DE_UNKNOWN, NULL, NULL);
    if (r != EOK)
        goto Finish;

    r = ext4_fs_get_inode_ref(&mp->fs, f.inode, &inode_ref);
    if (r != EOK)
        goto Finish;

    *atime = ext4_inode_get_access_time(inode_ref.inode);
    r = ext4_fs_put_inode_ref(&inode_ref);

    Finish:
    EXT4_MP_UNLOCK(mp);

    return r;
}

int ext4_mtime_get(const char *path, uint32_t *mtime)
{
    struct ext4_inode_ref inode_ref;
    struct ext4_mountpoint *mp = ext4_get_mount(path);
    ext4_file f;
    int r;

    if (!mp)
        return ENOENT;

    EXT4_MP_LOCK(mp);

    r = ext4_generic_open2(&f, path, O_RDONLY, EXT4_DE_UNKNOWN, NULL, NULL);
    if (r != EOK)
        goto Finish;

    r = ext4_fs_get_inode_ref(&mp->fs, f.inode, &inode_ref);
    if (r != EOK)
        goto Finish;

    *mtime = ext4_inode_get_modif_time(inode_ref.inode);
    r = ext4_fs_put_inode_ref(&inode_ref);

    Finish:
    EXT4_MP_UNLOCK(mp);

    return r;
}

int ext4_ctime_get(const char *path, uint32_t *ctime)
{
    struct ext4_inode_ref inode_ref;
    struct ext4_mountpoint *mp = ext4_get_mount(path);
    ext4_file f;
    int r;

    if (!mp)
        return ENOENT;

    EXT4_MP_LOCK(mp);

    r = ext4_generic_open2(&f, path, O_RDONLY, EXT4_DE_UNKNOWN, NULL, NULL);
    if (r != EOK)
        goto Finish;

    r = ext4_fs_get_inode_ref(&mp->fs, f.inode, &inode_ref);
    if (r != EOK)
        goto Finish;

    *ctime = ext4_inode_get_change_inode_time(inode_ref.inode);
    r = ext4_fs_put_inode_ref(&inode_ref);

    Finish:
    EXT4_MP_UNLOCK(mp);

    return r;
}

static int ext4_fsymlink_set(ext4_file *f, const void *buf, uint32_t size)
{
    struct ext4_inode_ref ref;
    uint32_t sblock;
    ext4_fsblk_t fblock;
    uint32_t block_size;
    int r;

    ext4_assert(f && f->mp);

    if (!size)
        return EOK;

    r = ext4_fs_get_inode_ref(&f->mp->fs, f->inode, &ref);
    if (r != EOK)
        return r;

    /*Sync file size*/
    block_size = ext4_sb_get_block_size(&f->mp->fs.sb);
    if (size > block_size) {
        r = EINVAL;
        goto Finish;
    }
    r = ext4_ftruncate_no_lock(f, 0);
    if (r != EOK)
        goto Finish;

    /*Start write back cache mode.*/
    r = ext4_block_cache_write_back(f->mp->fs.bdev, 1);
    if (r != EOK)
        goto Finish;

    /*If the size of symlink is smaller than 60 bytes*/
    if (size < sizeof(ref.inode->blocks)) {
        memset(ref.inode->blocks, 0, sizeof(ref.inode->blocks));
        memcpy(ref.inode->blocks, buf, size);
        ext4_inode_clear_flag(ref.inode, EXT4_INODE_FLAG_EXTENTS);
    } else {
        uint64_t off;
        ext4_fs_inode_blocks_init(&f->mp->fs, &ref);
        r = ext4_fs_append_inode_dblk(&ref, &fblock, &sblock);
        if (r != EOK)
            goto Finish;

        off = fblock * block_size;
        r = ext4_block_writebytes(f->mp->fs.bdev, off, buf, size);
        if (r != EOK)
            goto Finish;
    }

    /*Stop write back cache mode*/
    ext4_block_cache_write_back(f->mp->fs.bdev, 0);

    if (r != EOK)
        goto Finish;

    ext4_inode_set_size(ref.inode, size);
    ref.dirty = true;

    f->fsize = size;
    if (f->fpos > size)
        f->fpos = size;

Finish:
    ext4_fs_put_inode_ref(&ref);
    return r;
}

int ext4_fsymlink(const char *target, const char *path)
{
    struct ext4_mountpoint *mp = ext4_get_mount(path);
    int r;
    ext4_file f;
    int filetype;

    if (!mp)
        return ENOENT;

    if (mp->fs.read_only)
        return EROFS;

    filetype = EXT4_DE_SYMLINK;

    EXT4_MP_LOCK(mp);
    ext4_block_cache_write_back(mp->fs.bdev, 1);
    ext4_trans_start(mp);

    r = ext4_generic_open2(&f, path, O_RDWR | O_CREAT, filetype, NULL, NULL);
    if (r == EOK)
        r = ext4_fsymlink_set(&f, target, strlen(target));
    else
        goto Finish;

    ext4_fclose(&f);

Finish:
    if (r != EOK)
        ext4_trans_abort(mp);
    else
        ext4_trans_stop(mp);

    ext4_block_cache_write_back(mp->fs.bdev, 0);
    EXT4_MP_UNLOCK(mp);
    return r;
}

int ext4_readlink(const char *path, char *buf, size_t bufsize, size_t *rcnt)
{
    struct ext4_mountpoint *mp = ext4_get_mount(path);
    int r;
    ext4_file f;
    int filetype;

    if (!mp)
        return ENOENT;

    if (!buf)
        return EINVAL;

    filetype = EXT4_DE_SYMLINK;

    EXT4_MP_LOCK(mp);
    ext4_block_cache_write_back(mp->fs.bdev, 1);
    r = ext4_generic_open2(&f, path, O_RDONLY, filetype, NULL, NULL);
    if (r == EOK)
        r = ext4_fread(&f, buf, bufsize, rcnt);
    else
        goto Finish;

    ext4_fclose(&f);

Finish:
    ext4_block_cache_write_back(mp->fs.bdev, 0);
    EXT4_MP_UNLOCK(mp);
    return r;
}

static int ext4_mknod_set(ext4_file *f, uint32_t dev)
{
    struct ext4_inode_ref ref;
    int r;

    ext4_assert(f && f->mp);

    r = ext4_fs_get_inode_ref(&f->mp->fs, f->inode, &ref);
    if (r != EOK)
        return r;

    ext4_inode_set_dev(ref.inode, dev);

    ext4_inode_set_size(ref.inode, 0);
    ref.dirty = true;

    f->fsize = 0;
    f->fpos = 0;

    r = ext4_fs_put_inode_ref(&ref);
    return r;
}

int ext4_mknod(const char *path, int filetype, uint32_t dev)
{
    struct ext4_mountpoint *mp = ext4_get_mount(path);
    int r;
    ext4_file f;

    if (!mp)
        return ENOENT;

    if (mp->fs.read_only)
        return EROFS;

    /*
     * The filetype shouldn't be normal file, directory or
     * unknown.
     */
    if (filetype == EXT4_DE_UNKNOWN ||
        filetype == EXT4_DE_REG_FILE ||
        filetype == EXT4_DE_DIR ||
        filetype == EXT4_DE_SYMLINK)
        return EINVAL;

    /*
     * Nor should it be any bogus value.
     */
    if (filetype != EXT4_DE_CHRDEV &&
        filetype != EXT4_DE_BLKDEV &&
        filetype != EXT4_DE_FIFO &&
        filetype != EXT4_DE_SOCK)
        return EINVAL;

    EXT4_MP_LOCK(mp);
    ext4_block_cache_write_back(mp->fs.bdev, 1);
    ext4_trans_start(mp);

    r = ext4_generic_open2(&f, path, O_RDWR | O_CREAT, filetype, NULL, NULL);
    if (r == EOK) {
        if (filetype == EXT4_DE_CHRDEV ||
            filetype == EXT4_DE_BLKDEV)
            r = ext4_mknod_set(&f, dev);
    } else {
        goto Finish;
    }

    ext4_fclose(&f);

Finish:
    if (r != EOK)
        ext4_trans_abort(mp);
    else
        ext4_trans_stop(mp);

    ext4_block_cache_write_back(mp->fs.bdev, 0);
    EXT4_MP_UNLOCK(mp);
    return r;
}

int ext4_setxattr(const char *path, const char *name, size_t name_len,
          const void *data, size_t data_size)
{
    bool found;
    int r = EOK;
    ext4_file f;
    uint32_t inode;
    uint8_t name_index;
    const char *dissected_name = NULL;
    size_t dissected_len = 0;
    struct ext4_inode_ref inode_ref;
    struct ext4_mountpoint *mp = ext4_get_mount(path);
    if (!mp)
        return ENOENT;

    if (mp->fs.read_only)
        return EROFS;

    dissected_name = ext4_extract_xattr_name(name, name_len,
                &name_index, &dissected_len,
                &found);
    if (!found)
        return EINVAL;

    EXT4_MP_LOCK(mp);
    r = ext4_generic_open2(&f, path, O_RDONLY, EXT4_DE_UNKNOWN, NULL, NULL);
    if (r != EOK) {
        EXT4_MP_UNLOCK(mp);
        return r;
    }

    inode = f.inode;
    ext4_fclose(&f);
    ext4_trans_start(mp);

    r = ext4_fs_get_inode_ref(&mp->fs, inode, &inode_ref);
    if (r != EOK)
        goto Finish;

    r = ext4_xattr_set(&inode_ref, name_index, dissected_name,
            dissected_len, data, data_size);

    ext4_fs_put_inode_ref(&inode_ref);
Finish:
    if (r != EOK)
        ext4_trans_abort(mp);
    else
        ext4_trans_stop(mp);

    EXT4_MP_UNLOCK(mp);
    return r;
}

int ext4_getxattr(const char *path, const char *name, size_t name_len,
          void *buf, size_t buf_size, size_t *data_size)
{
    bool found;
    int r = EOK;
    ext4_file f;
    uint32_t inode;
    uint8_t name_index;
    const char *dissected_name = NULL;
    size_t dissected_len = 0;
    struct ext4_inode_ref inode_ref;
    struct ext4_mountpoint *mp = ext4_get_mount(path);
    if (!mp)
        return ENOENT;

    dissected_name = ext4_extract_xattr_name(name, name_len,
                &name_index, &dissected_len,
                &found);
    if (!found)
        return EINVAL;

    EXT4_MP_LOCK(mp);
    r = ext4_generic_open2(&f, path, O_RDONLY, EXT4_DE_UNKNOWN, NULL, NULL);
    if (r != EOK)
        goto Finish;

    inode = f.inode;
    ext4_fclose(&f);

    r = ext4_fs_get_inode_ref(&mp->fs, inode, &inode_ref);
    if (r != EOK)
        goto Finish;

    r = ext4_xattr_get(&inode_ref, name_index, dissected_name,
                dissected_len, buf, buf_size, data_size);

    ext4_fs_put_inode_ref(&inode_ref);
Finish:
    EXT4_MP_UNLOCK(mp);
    return r;
}

int ext4_listxattr(const char *path, char *list, size_t size, size_t *ret_size)
{
    int r = EOK;
    ext4_file f;
    uint32_t inode;
    size_t list_len, list_size = 0;
    struct ext4_inode_ref inode_ref;
    struct ext4_xattr_list_entry *xattr_list = NULL,
                     *entry = NULL;
    struct ext4_mountpoint *mp = ext4_get_mount(path);
    if (!mp)
        return ENOENT;

    EXT4_MP_LOCK(mp);
    r = ext4_generic_open2(&f, path, O_RDONLY, EXT4_DE_UNKNOWN, NULL, NULL);
    if (r != EOK)
        goto Finish;
    inode = f.inode;
    ext4_fclose(&f);

    r = ext4_fs_get_inode_ref(&mp->fs, inode, &inode_ref);
    if (r != EOK)
        goto Finish;

    r = ext4_xattr_list(&inode_ref, NULL, &list_len);
    if (r == EOK && list_len) {
        xattr_list = ext4_malloc(list_len);
        if (!xattr_list) {
            ext4_fs_put_inode_ref(&inode_ref);
            r = ENOMEM;
            goto Finish;
        }
        entry = xattr_list;
        r = ext4_xattr_list(&inode_ref, entry, &list_len);
        if (r != EOK) {
            ext4_fs_put_inode_ref(&inode_ref);
            goto Finish;
        }

        for (;entry;entry = entry->next) {
            size_t prefix_len;
            const char *prefix =
                ext4_get_xattr_name_prefix(entry->name_index,
                               &prefix_len);
            if (size) {
                if (prefix_len + entry->name_len + 1 > size) {
                    ext4_fs_put_inode_ref(&inode_ref);
                    r = ERANGE;
                    goto Finish;
                }
            }

            if (list && size) {
                memcpy(list, prefix, prefix_len);
                list += prefix_len;
                memcpy(list, entry->name,
                    entry->name_len);
                list[entry->name_len] = 0;
                list += entry->name_len + 1;

                size -= prefix_len + entry->name_len + 1;
            }

            list_size += prefix_len + entry->name_len + 1;
        }
        if (ret_size)
            *ret_size = list_size;

    }
    ext4_fs_put_inode_ref(&inode_ref);
Finish:
    EXT4_MP_UNLOCK(mp);
    if (xattr_list)
        ext4_free(xattr_list);

    return r;

}

int ext4_removexattr(const char *path, const char *name, size_t name_len)
{
    bool found;
    int r = EOK;
    ext4_file f;
    uint32_t inode;
    uint8_t name_index;
    const char *dissected_name = NULL;
    size_t dissected_len = 0;
    struct ext4_inode_ref inode_ref;
    struct ext4_mountpoint *mp = ext4_get_mount(path);
    if (!mp)
        return ENOENT;

    if (mp->fs.read_only)
        return EROFS;

    dissected_name = ext4_extract_xattr_name(name, name_len,
                        &name_index, &dissected_len,
                        &found);
    if (!found)
        return EINVAL;

    EXT4_MP_LOCK(mp);
    r = ext4_generic_open2(&f, path, O_RDONLY, EXT4_DE_UNKNOWN, NULL, NULL);
    if (r != EOK) {
        EXT4_MP_LOCK(mp);
        return r;
    }

    inode = f.inode;
    ext4_fclose(&f);
    ext4_trans_start(mp);

    r = ext4_fs_get_inode_ref(&mp->fs, inode, &inode_ref);
    if (r != EOK)
        goto Finish;

    r = ext4_xattr_remove(&inode_ref, name_index, dissected_name,
                  dissected_len);

    ext4_fs_put_inode_ref(&inode_ref);
Finish:
    if (r != EOK)
        ext4_trans_abort(mp);
    else
        ext4_trans_stop(mp);

    EXT4_MP_UNLOCK(mp);
    return r;

}

/*********************************DIRECTORY OPERATION************************/

int ext4_dir_rm(const char *path)
{
    int r;
    int len;
    ext4_file f;

    struct ext4_mountpoint *mp = ext4_get_mount(path);
    struct ext4_inode_ref act;
    struct ext4_inode_ref child;
    struct ext4_dir_iter it;

    uint32_t name_off;
    uint32_t inode_up;
    uint32_t inode_current;
    uint32_t depth = 1;

    bool has_children;
    bool is_goal;
    bool dir_end;

    if (!mp)
        return ENOENT;

    if (mp->fs.read_only)
        return EROFS;

    EXT4_MP_LOCK(mp);

    struct ext4_fs *const fs = &mp->fs;

    /*Check if exist.*/
    r = ext4_generic_open(&f, path, "r", false, &inode_up, &name_off);
    if (r != EOK) {
        EXT4_MP_UNLOCK(mp);
        return r;
    }

    path += name_off;
    if(path[0] == '/')
    {
        path += 1;
    }

    len = ext4_path_check(path, &is_goal);
    inode_current = f.inode;

    ext4_block_cache_write_back(mp->fs.bdev, 1);

    do {

        uint64_t act_curr_pos = 0;
        has_children = false;
        dir_end = false;

        while (r == EOK && !has_children && !dir_end) {

            /*Load directory node.*/
            r = ext4_fs_get_inode_ref(fs, inode_current, &act);
            if (r != EOK) {
                break;
            }

            /*Initialize iterator.*/
            r = ext4_dir_iterator_init(&it, &act, act_curr_pos);
            if (r != EOK) {
                ext4_fs_put_inode_ref(&act);
                break;
            }

            if (!it.curr) {
                dir_end = true;
                goto End;
            }

            ext4_trans_start(mp);

            /*Get up directory inode when ".." entry*/
            if ((it.curr->name_len == 2) &&
                ext4_is_dots(it.curr->name, it.curr->name_len)) {
                inode_up = ext4_dir_en_get_inode(it.curr);
            }

            /*If directory or file entry,  but not "." ".." entry*/
            if (!ext4_is_dots(it.curr->name, it.curr->name_len)) {

                /*Get child inode reference do unlink
                 * directory/file.*/
                uint32_t cinode;
                uint32_t inode_type;
                cinode = ext4_dir_en_get_inode(it.curr);
                r = ext4_fs_get_inode_ref(fs, cinode, &child);
                if (r != EOK)
                    goto End;

                /*If directory with no leaf children*/
                r = ext4_has_children(&has_children, &child);
                if (r != EOK) {
                    ext4_fs_put_inode_ref(&child);
                    goto End;
                }

                if (has_children) {
                    /*Has directory children. Go into this
                     * directory.*/
                    inode_up = inode_current;
                    inode_current = cinode;
                    depth++;
                    ext4_fs_put_inode_ref(&child);
                    goto End;
                }
                inode_type = ext4_inode_type(&mp->fs.sb,
                        child.inode);

                /* Truncate */
                if (inode_type != EXT4_INODE_MODE_DIRECTORY)
                    r = ext4_trunc_inode(mp, child.index, 0);
                else
                    r = ext4_trunc_dir(mp, &act, &child);

                if (r != EOK) {
                    ext4_fs_put_inode_ref(&child);
                    goto End;
                }

                /*No children in child directory or file. Just
                 * unlink.*/
                r = ext4_unlink(f.mp, &act, &child,
                        (char *)it.curr->name,
                        it.curr->name_len);
                if (r != EOK) {
                    ext4_fs_put_inode_ref(&child);
                    goto End;
                }

                ext4_inode_set_del_time(child.inode, -1L);
                ext4_inode_set_links_cnt(child.inode, 0);
                child.dirty = true;

                r = ext4_fs_free_inode(&child);
                if (r != EOK) {
                    ext4_fs_put_inode_ref(&child);
                    goto End;
                }

                r = ext4_fs_put_inode_ref(&child);
                if (r != EOK)
                    goto End;

            }

            r = ext4_dir_iterator_next(&it);
            if (r != EOK)
                goto End;

            act_curr_pos = it.curr_off;
End:
            ext4_dir_iterator_fini(&it);
            if (r == EOK)
                r = ext4_fs_put_inode_ref(&act);
            else
                ext4_fs_put_inode_ref(&act);

            if (r != EOK)
                ext4_trans_abort(mp);
            else
                ext4_trans_stop(mp);
        }

        if (dir_end) {
            /*Directory iterator reached last entry*/
            depth--;
            if (depth)
                inode_current = inode_up;

        }

        if (r != EOK)
            break;

    } while (depth);

    /*Last unlink*/
    if (r == EOK && !depth) {
        /*Load parent.*/
        struct ext4_inode_ref parent;
        r = ext4_fs_get_inode_ref(&f.mp->fs, inode_up,
                &parent);
        if (r != EOK)
            goto Finish;
        r = ext4_fs_get_inode_ref(&f.mp->fs, inode_current,
                &act);
        if (r != EOK) {
            ext4_fs_put_inode_ref(&act);
            goto Finish;
        }

        ext4_trans_start(mp);

        /* In this place all directories should be
         * unlinked.
         * Last unlink from root of current directory*/
        r = ext4_unlink(f.mp, &parent, &act,
                (char *)path, len);
        if (r != EOK) {
            ext4_fs_put_inode_ref(&parent);
            ext4_fs_put_inode_ref(&act);
            goto Finish;
        }

        if (ext4_inode_get_links_cnt(act.inode) == 2) {
            ext4_inode_set_del_time(act.inode, -1L);
            ext4_inode_set_links_cnt(act.inode, 0);
            act.dirty = true;
            /*Truncate*/
            r = ext4_trunc_dir(mp, &parent, &act);
            if (r != EOK) {
                ext4_fs_put_inode_ref(&parent);
                ext4_fs_put_inode_ref(&act);
                goto Finish;
            }

            r = ext4_fs_free_inode(&act);
            if (r != EOK) {
                ext4_fs_put_inode_ref(&parent);
                ext4_fs_put_inode_ref(&act);
                goto Finish;
            }
        }

        r = ext4_fs_put_inode_ref(&parent);
        if (r != EOK)
            goto Finish;

        r = ext4_fs_put_inode_ref(&act);
    Finish:
        if (r != EOK)
            ext4_trans_abort(mp);
        else
            ext4_trans_stop(mp);
    }

    ext4_block_cache_write_back(mp->fs.bdev, 0);
    EXT4_MP_UNLOCK(mp);

    return r;
}

int ext4_dir_mv(const char *path, const char *new_path)
{
    return ext4_frename(path, new_path);
}

int ext4_dir_mk(const char *path)
{
    int r;
    ext4_file f;
    struct ext4_mountpoint *mp = ext4_get_mount(path);

    if (!mp)
        return ENOENT;

    if (mp->fs.read_only)
        return EROFS;

    EXT4_MP_LOCK(mp);

    /*Check if exist.*/
    r = ext4_generic_open(&f, path, "r", false, 0, 0);
    if (r == EOK)
        goto Finish;

    /*Create new directory.*/
    r = ext4_generic_open(&f, path, "w", false, 0, 0);

Finish:
    EXT4_MP_UNLOCK(mp);
    return r;
}

int ext4_dir_open(ext4_dir *dir, const char *path)
{
    struct ext4_mountpoint *mp = ext4_get_mount(path);

    int r;

    if (!mp)
        return ENOENT;

    EXT4_MP_LOCK(mp);
    r = ext4_generic_open(&dir->f, path, "r", false, 0, 0);
    dir->next_off = 0;
    EXT4_MP_UNLOCK(mp);
    return r;
}

int ext4_dir_close(ext4_dir *dir)
{
    return ext4_fclose(&dir->f);
}

const ext4_direntry *ext4_dir_entry_next(ext4_dir *dir)
{
#define EXT4_DIR_ENTRY_OFFSET_TERM (uint64_t)(-1)

    int r;
    uint16_t name_length;
    ext4_direntry *de = 0;
    struct ext4_inode_ref dir_inode;
    struct ext4_dir_iter it;

    EXT4_MP_LOCK(dir->f.mp);

    if (dir->next_off == EXT4_DIR_ENTRY_OFFSET_TERM) {
        EXT4_MP_UNLOCK(dir->f.mp);
        return 0;
    }

    r = ext4_fs_get_inode_ref(&dir->f.mp->fs, dir->f.inode, &dir_inode);
    if (r != EOK) {
        goto Finish;
    }

    r = ext4_dir_iterator_init(&it, &dir_inode, dir->next_off);
    if (r != EOK) {
        ext4_fs_put_inode_ref(&dir_inode);
        goto Finish;
    }

    memset(&dir->de.name, 0, sizeof(dir->de.name));
    name_length = ext4_dir_en_get_name_len(&dir->f.mp->fs.sb,
                           it.curr);
    memcpy(&dir->de.name, it.curr->name, name_length);

    /* Directly copying the content isn't safe for Big-endian targets*/
    dir->de.inode = ext4_dir_en_get_inode(it.curr);
    dir->de.entry_length = ext4_dir_en_get_entry_len(it.curr);
    dir->de.name_length = name_length;
    dir->de.inode_type = ext4_dir_en_get_inode_type(&dir->f.mp->fs.sb,
                              it.curr);

    de = &dir->de;

    ext4_dir_iterator_next(&it);

    dir->next_off = it.curr ? it.curr_off : EXT4_DIR_ENTRY_OFFSET_TERM;

    ext4_dir_iterator_fini(&it);
    ext4_fs_put_inode_ref(&dir_inode);

Finish:
    EXT4_MP_UNLOCK(dir->f.mp);
    return de;
}

void ext4_dir_entry_rewind(ext4_dir *dir)
{
    dir->next_off = 0;
}

/**
 * @}
 */
